Effects of Inbreeding on Mortality in the Domestic Fowl

WITH increased emphasis being placed on the production of poultry and eggs by incrossbreeding methods, it is desirable to know more about the influence of inbreeding on the economically important traits of poultry. This study deals with the relationship of inbreeding to mortality. Wilson (1948) reported a regression of −0.19 of percent hatchability on inbreeding among the inbred Leghorns at the Iowa Agricultural Experiment Station. Stephenson (1949) reported a regression of −0.43 of percent egg production on inbreeding in the same flock. Düzgünes (1950) studied the regression of mortality on inbreeding in Leghorns. He found a significant regression up to 5 months of age, but no significant regression thereafter. Several studies have indicated a depression effect of inbreeding on viability in chickens. Dryden (1915) found that inbreeding increased mortality in both chicks and hens. Cole and Halpin (1916 Cole and Halpin (1922), after inbreeding Rhode Island Reds for four years, were forced to …